It is known to deliver hydraulic valve lash adjusters configured as roller tappets that have already been installed in anti-rotation bridges, together with these, to engine manufacturing plants and to mount them there on internal combustion engines. For instance, anti-rotation bridges made to U.S. Pat. No. 5,088,455 are bought as manufactured components and fitted with several roller tappets and a screw for fixing the anti-rotation bridge on an engine housing, and are then supplied as a complete assembly to the engine manufacturer. This, however, necessitates a double transportation locking device for the hydraulic components in each roller tappet. This is achieved firstly through the chucking force acting between the key surfaces of the roller tappet and the corresponding surfaces of the bridge and secondly through a locking ring installed in the roller tappet. This results in an expensive construction because cost-intensive work steps are required for the fabrication and an additional component has to be arranged in the roller tappet.
A valve train of the aforesaid type is known from the document DE 102 12 522 A1. As shown in FIGS. 6 and 7 of this document, the roller tappet that is inserted into an anti-rotation bridge comprises an outer section that is retained for axial displacement in the bridge and an inner section that is retained for axial displacement in a bore of the outer section. The inner section is formed by a piston that is divided along a transverse plane into a lower piston part and an upper piston part. To assure that the inner section does not come loose during mounting and transportation but remains in the outer section, an additional component in the form of a locking ring that holds the upper piston part fast is inserted into an inner circumferential groove of the outer section.